1. Field of the Invention
The present invention relates to an air conditioner capable of separately controlling the temperatures of the conditioned air flows blown into the first and second air conditioning zones in a vehicle passenger compartment.
2. Description of the Related Art
As will be seen, for instance, from the disclosure in a Japanese Unexamined Patent Publication (Kokai) No. Hei 5-213050, there is already known a vehicular air conditioner which can separately control the temperatures of the conditioned air flows blown into the driver's seat side (first air conditioning zone) and the same blown to the passenger's seat side (second air conditioning zone).
More concretely, in the vehicular air conditioner of this kind, there are provided a driver's seat side air conditioning duct (first air passage) and an passenger's seat side air conditioning duct (second air passage) in correspondence with said respective seat sides and, in these respective air conditioning air ducts, there are provided first and second temperature regulating means for regulating the temperature of the air in said ducts. At the downstream end of said driver's seat side air conditioning duct, there are arranged a first face air outlet for blowing the conditioned air directing to the upper half of the driver's body and a first foot air outlet for blowing the conditioned air directing to the driver's foot area. Also, at the downstream end of the passenger's seat side air conditioning duct, there are arranged a second face air outlet for blowing the conditioned air directing to the upper half of the passenger's body and a second foot air outlet for blowing the conditioned air directing to the passenger's foot area.
First and second target air temperatures at said respective seat sides are calculated based on the respective setting temperatures set by the temperature setting devices (first and second temperature setting means), which are provided corresponding to said respective seat sides, and the temperatures measured on the respective seat sides. Said respective temperature regulating means are separately controlled in such a manner that the temperatures of the conditioned air blown to said respective seat sides come to said calculated first and second target blowing temperatures, thereby separately controlling the blowing temperatures to the respective seat sides.
At the downstream end of the driver's seat side air conditioning duct, there is further provided a driver's seat side air outlet changeover door (the air volume proportion regulating means) for regulating the air volume proportion of the air volume blown from said first face air outlet to the same from said first foot air outlet, so-called, for regulating a driver's seat side blowing mode. Similarly, at the downstream end of the passenger's seat side air conditioning duct, there is provided the passenger's seat side air outlet changeover door (the air volume proportion regulating means) for regulating the air volume proportion of the air volume blown from said second face air outlet to the same from said second foot air outlet, so-called, for regulating the passenger's seat side blowing mode.
From the characteristics as shown in FIG. 6, the driver's seat side blowing mode is determined based on said first target blowing temperature, and similarly, from said characteristics of FIG. 6, the passenger's seat side blowing mode is determined based on said second target blowing temperature. Thus, the respective blowing modes are separately set.
In the air conditioner as constituted as above, for instance, the driver's seat side setting temperature and the passenger's seat side temperature can be very different from each other, so that, the first target blowing temperature is low (e.g. T1 in FIG. 6) and the second target blowing temperature is high (e.g. T2 in FIG. 6). Even in such a case, the driver's seat side blowing mode and the passenger's seat side blowing mode can still be set to be the face mode and the foot mode, respectively, and thus, the blowing modes for the seats become the modes to obtain the respective blowing temperatures.
Recently, however, a vehicular air conditioner of a low cost type is drawing the attention of those skilled in the art, in contrast to the above mentioned vehicular air conditioner. In case of the latter air conditioner, as described in the above, air outlet changeover doors (blowing air volume proportion regulating means) are provided corresponding to respective seat sides, thus enabling respective blowing modes to be separately controlled. In said air conditioner of the low cost type, however, the blowing modes to respective seat sides are controlled by a common air outlet changeover door, thereby making the blowing modes to respective seat sides the same.
In the air conditioner of this type, since the blowing mode has to be made common to respective seat sides even though said first target blowing temperature is different from said second one, a suitable way to meet such requirement must be found, for instance, a method of calculating a mean value from the first and second blowing temperatures in such a manner that the blowing mode satisfies both of said target blowing temperatures to the utmost, and setting the blowing mode based on said calculated mean value and the characteristics of FIG. 6.
In this case, however, assuming that, for instance, the first target blowing temperature is the said T1, the second one is T2, and the mean value of T1 and T2 is T3, the blowing mode based on this T3 is determined as the face mode from the characteristics of FIG. 6. As a result of this, the cold air is supplied to the driver's seat side from the face air outlet, thus no problem occurs in this respect. However, as to the passenger's seat side, the warm air is supplied to the passenger's seat side from the face air outlet, so that he might feel uncomfortable.
Also, assuming that the mean value of said T1 and T2 is higher than said T3 and the blowing mode based on this mean value is the foot mode, the warm air is supplied to the passenger's seat side from the foot air outlet, thus there being no problem in this respect, but as to the driver's seat side, the cold air is supplied to the driver from the foot air outlet, so that he might feel uncomfortable.